Add y_sort_offset

comfy-core/src/lib.rs

@@ -633,6 +633,7 @@ pub struct Mesh {
     pub indices: SmallVec<[u32; 6]>,
     pub z_index: i32,
     pub texture: Option<TextureHandle>,
+    pub y_sort_offset: f32,
 }
 
 #[repr(C)]

comfy-core/src/quad.rs

@@ -185,6 +185,10 @@ pub struct DrawTextureProParams {
     pub blend_mode: BlendMode,
     /// Rotation around the x axis for creating a 3d effect.
     pub rotation_x: f32,
+    /// Offset for y-sorting in world-space. This is useful for when sprites have different
+    /// sizes and pivots, for example when a tree should be "behind" something based on its bottom-most
+    /// pixel, and not based on its size.
+    pub y_sort_offset: f32,
 }
 
 impl Default for DrawTextureProParams {
@@ -199,6 +203,7 @@ impl Default for DrawTextureProParams {
             flip_y: false,
             blend_mode: Default::default(),
             rotation_x: 0.0,
+            y_sort_offset: 0.0,
         }
     }
 }

comfy-wgpu/src/batching.rs

@@ -40,7 +40,9 @@ pub fn run_batched_render_passes(
 
         // TODO: add this back later
         if get_y_sort(key.z_index) {
-            meshes.sort_by_key(|mesh| OrderedFloat::<f32>(-mesh.origin.y));
+            meshes.sort_by_key(|mesh| {
+                OrderedFloat::<f32>(-(mesh.origin.y + mesh.y_sort_offset))
+            });
         }
 
         render_meshes(